Kite Tests on Land and Water

Lifting kite testing: rok G9 & fled – May 6

5/6/11

Today we took the inflatable lifting kites out to Crown Beach to test them with Armand. Dudu and Armand flew the most recent rokkaku, the G9, in about 15 knot winds and used it to lift a payload of sand. The front spar on the G9 kite is fused to the center strut, while the back spar is free to rotate, as on the G8 kite. There is a tube that links the back spar to the center strut at the cross point, and this allows the entire kite to be inflated via one rear valve. We loaded the kite with sand bags until it began to deform, and then observed the flight pattern with that weight suspended from the […more]

Beach kite test with Pete Lynn – Apr 13

4/13/11

Today we went to the beach to test the new 12 sqm kite that Pete designed. The bridle on this kite is designed to distribute loads in a new way, so the kite can take higher loads without deforming. As you can see from the profile, this kite is flatter than our other C-shaped kites, which is a feature we think will help withstand load.

The goal of this test was to gather information to improve upon the kite enough that we can scale it up for use on the boats. On Monday, Don kitesurfed with the kite on his own, and yesterday Pete and Dudu tested the kite together. Today Pete and Don both surfed with the kite, returning […more]

Rokkaku & Android camera setup test – Mar 31

3/31/11

We took the “good” kite from the last two rokkaku tests out to the parking lot to compare its performance to that of the original carbon spar kite in very low wind.

Additionally, Jamie debuted his Android phone camera system by attaching one phone, in a padded cardboard box, to the kite line of the carbon-sparred kite and letting it out about 75m. In his hand he held another Android phone, which displayed the image taken by the lofted camera.

Meanwhile, Don and Dudu discussed weight differences in the two kites and experimented with bridle positions on the inflatable one. We also briefly attached a GoPro to the line of the inflatable kite to get an aerial view of the […more]

Rokkaku kite test – Mar 28

3/28/11

Dudu, Jamie and Renata tested two Rokkaku kites today, both with inflatable cuben fiber struts. Kite A was the best one from Friday (#4), which had 50% of the original curvature, 90% of the original diameter, and long battens. Kite B was a new one with the same tube diameter, 75% of the original curvature, and short battens.

From Dudu:
Both kites flew well with the same stability and held all gusts with no issue. The 50% kite still had better flying angle.
This test proved we can have smaller battens at strut tube tips and still spread the loads. This can save weight and storage.

Rokkaku kite test – Mar 25

3/25/11

We took four different rokkaku kites out to the parking lot today to compare their performances. Kite 1 (photos 1, 8, 12-15) was the original rokkaku with all-carbon spars. Kite 2 (photos 1, 8, 11-12) was similar but with a modified spine. We also hung a camera off the line of this kite to film Kite 3. Kite 3 (photos 1, 8-10) had an identical canopy to 1 & 2, but instead of carbon spars, it had inflatable spars made of cuben fiber. The inflatable spars had the same curvature as the original carbons spars. Kite 4 (photos 3-7) was also made from an identical canopy and also had inflatable spars made of cuben fiber. However, these spars were 90% […more]

110 sqm Kite test videos

7/12/10

Here are 2 interesting videos from Bob Dill, who came with us on the 110 sqm kite test aboard Cheyenne.

The first video is the water launch. With Joe and Roland in the water, trying to hold and position the kite, it shows the perspective of just how big the kite is.

The second video is what happened as soon as the kite became overloaded. The surface ‘balloons’ due to the skin loading, which leads to the tips buckling. This then in turn puts a large pitching moment into the foil, which pushes the leading edge of the tips in, and tries to collapse the kite.

Kai View  Data:
20100701-k1-50meter-single.kai.bz2